Plane-polarized electromagnetic waves

Consider a plane-polarised electromagnetic wave in source-free vacuum, with magnetic field B = (1,1,0)BoCos(kz-wt), with Bo = 0.001 Tesla. Find
(1) the direction of propagation of the wave,
(2) average energy density carried by the wave, and
(3) the fraction of this energy which would pass through a perfect polariod sheet at normal incidence, if the angle between B and the transmission axis of the polariser is 30degrees.